The great catastrophe: causes of the Permo-Triassic marine mass extinctionOA

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the cr...     

Save China's Wild Bees,Safeguard Global Food Supply

正China has so far avoided the massive losses of bees seen in the West,but the country's diverse range of native bees face their own set of growing threats.A new study argues that these threats could have disastrous consequences for global food security and biodiversity.The alarming decline of bee populations in the United States and Europe has rightfully been drawing     

Late Ordovician Mass Extinction: Earth,fire and iceOA

The Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and intr...     

Climbing robots for manufacturingOA

Robotized intelligent manufacturing is a growing trend in the manufacturing of large and complex components in aviation,aerospace,marine engineering and other industries.With their expansive workspaces and flexible deployment,climbing manufacturing robots can create a revolutionary manufacturing paradigm for large and complex components.This paper defines the climbing manufacturing robot based on the application status of climbing robots and then analyzes four key technical re quirements:adhesio...     

An Algorithm for Early Warning of Tsunami

The Dec. 26, 2004 earthquake under the Indian Ocean floor triggered an outbreak of devastating tsunami,leading to incredible damages and tragic losses of life in littoral countries. Records showed that the killer tsunami reached the seaside Indonesian islands after half an hour, and within several hours it reached the beach lands of Sri Lanka, Thailand and other countries at the rim of the Ocean.     

Revisiting non-linear Thomson scattering with metamaterialsOA

<正>Non-linear optics is a branch of optics that studies the intriguing and sometimes unexpected ways in which light and matter interact at high intensities, when the polarization density does not respond linearly to the electric field of the light. The pursuit of the perfect non-linear optical material has been ongoing ever since the pioneering experiment on second harmonic generation carried out by Franken in 1961 [1]. Indeed,     

An Algorithm for Early Warning of Tsunami

The Dec. 26, 2004 earth-quake under the IndianOcean floor triggered anoutbreak of devastating tsunami,leading to incredible damages andtragic losses of life in littoralcountries. Records showed that thekiller tsunami reached the seasideIndonesian islands after half anhour, and within several hours itreached the beach lands of SriLanka, Thailand and other countriesat the rim of the Ocean.While earthquakes are some-what unpredictable, and always be-yond our control, according toexperts, earth…     

On“Essential Technical Feature”in Claims

In a patent application document, the claims are legally most important. When drafting them, we often pick our words and sentence patterns with great caution. Particularly, we need to carefully choose each technical features to be incorporated in the claims when drafting the independent claim. Incorporation of some unnecessary technical features in the claims would inevitably result in narrowed extent of protection, causing losses to the patentee. Conversely, missing of     

Bioprocess inspired formation of calcite mesocrystals by cation-mediated particle attachment mechanismOA

Calcite mesocrystals were proposed, and have been widely reported, to form in the presence of polymer additives via oriented assembly of nanoparticles. However, the formation mechanism and the role of polymer additives remain elusive. Here, inspired by the biomineralization process of sea urchin spine comprising magnesium calcite mesocrystals, we show that calcite mesocrystals could also be obtained via atachment of amorphous calcium carbonate(ACC) nanoparticles in the presence of inorganic zinc...     

Quantized Anomalous Hall Effect in Magnetic Topological Insulators

The Hall effect, the anomalous Hall effect (AHE) and the spin Hall effect are fundamental transport processes in solids arising from the Lorentz force and the spin-orbit coupling respectively. The AHE, in which a voltage transverse to the electric current appears even in the absence of an external magnetic field, was first detected in ferromagnetic (FM) metals in 1881 and later found to arise from the spin-orbit coupling (SOC) between the current and magnetic moments.     

A Support System to Tie Apron Strings to Debris Flow

Scientists from the Chengdu-based CAS Institute ofMountain Hazards and En-vironment (IMHE) recently workedout a decision-making support sys-tem for disaster mitigation on de-bris fans in mountainous regions.As a domestic vanguard, the sys-tem plays a key role in the fightagainst debris flow and helping toreduce casualties.Mud-rock flows cause devastat-ing losses in mountain areas, espe-cially in those places under increas-ingly fast economic developmentagainst a background of surging ur-ba…     

CAS scientists active in earthquake relief operation

Soon after the devastating earthquake taking place on last 12 May in Sichuan, the CAS leadership promptly mobilized its researchers to dedicate their expertise to the nationwide drive of the disaster＇s relief and reduction. A leading group was established to coordinate the Academy＇s efforts in this regard. All of the eight CAS institutions located in Sichuan were organized to do everything possible to reduce their losses to the minimum. At the same time, a trans-departmental and interdisciplinary taskforce was formed to provide a powerful S＆T backing for the nationwide drive.     

Evolution of artificial ion channelsOA

<正>Protein ion channels on a cell membrane generate action potentials for cellular signal transduction, and regulate biological activities during life. Since the discovery of the asymmetric ion transport phenomenon in quartz nanopipettes by Bard and colleagues [1], synthetic nanofluidic materials and devices have attracted a lot of research interests from the scientific community,     

Multi-region calcium imaging in freely behaving mice with ultra-compact head-mounted fluorescence microscopesOA

To investigate the circuit-level neural mechanisms of behavior, simultaneous imaging of neuronal activity in multiple cortical and subcortical regions is highly desired. Miniature head-mounted microscopes offer the capability of calcium imaging in freely behaving animals. However, implanting multiple microscopes on a mouse brain remains challenging due to space constraints and the cumbersome weight of the equipment.Here, we present TINIscope, a Tightly Integrated Neuronal Imaging microscope opti...     

Superscattering of water wavesOA

Inspired by the concept of superscattering in optics,we for the first time theoretically predict and experimentally demonstrate the superscattering phenomenon in water waves.The subwavelength superscatterer is constructed by multi-layered concentric cylinders with an inhomogeneous depth profile.The superscatterer breaks the long-held single-channel scattering limit by several times and thus significantly enhances the total scattering strength.The underlying mechanism originates from the near deg...     

Data quantity governance for machine learning in materials scienceOA

Data-driven machine learning(ML) is widely employed in the analysis of materials structure-activity relationships,performance optimization and materials design due to its superior ability to reveal latent data patterns and make accurate prediction.However,because of the laborious process of materials data acquisition,ML models encounter the issue of the mismatch between a high dimension of feature space and a small sample size(for traditional ML models) or the mismatch between model parameters a...     

High-timing-precision detection of single X-ray photons by superconducting nanowiresOA

Precisely acquiring the timing information of individual X-ray photons is important in both fundamental research and practical applications. The timing precision of commonly used X-ray single-photon detectors remains in the range of one hundred picoseconds to microseconds. In this work, we report on high-timing-precision detection of single X-ray photons through the fast transition to the normal state from the superconductive state of superconducting nanowires. We successfully demonstrate a free...     

Robotic mobile and mirror milling of large-scale complex structuresOA

<正>Large-scale complex structures,such as spacecraft cabins,aircraft composite skins and launch vehicle fuel tanks,are the core components of the equipment in aerospace,energy,shipbuilding and other fields.Their milling quality and efficiency are factors directly affecting the performance and productivity of spacecraft,aircraft and other key equipment.This kind of structure generally features large dimension,high accuracy,